Electric and magnetic properties of Bi substituted cobalt ferrite nanoparticles: Evolution of grain effect

Abstract

We have prepared Bismuth substituted nano-cobalt ferrite (CoFe2−xBixO4, x=0, 0.05, 0.1, 0.15) by auto combustion technique. The single phase XRD pattern confirmed the successful substitution of the larger cation. Surface morphology from FESEM image indicated the control particle growth (50–160nm) as a result of bismuth substitution. The increased particle size has effectively modified the electrical properties of the system in three major ways: (a) increase in resistivity, (b) evolution of grain relaxation and (c) reduction in dielectric loss and surface conduction. Additionally, magnetic behavior is also affected due to control particle growth. Magnetic hysteresis study at room temperature confirmed the rise in saturation magnetization (MS=74.5–86.5emu/g) and reduction in coercivity (HC=1633–1524Oe).